Title (fr)

Publication

Application

Priority

DE 19756248 A 19971217

EP 9807878 W 19981203

Abstract (en)

[origin: DE19756248A1] A brake booster/master cylinder unit (10) for a hydraulic motor vehicle brake system comprising a master cylinder (14) with a housing (32) containing a bore hole (34). A piston (36) is moveably and sealingly guided in said bore hole (34) and mechanically connected to a bar-shaped actuating member (30) to transmit an input force from the brake booster (12) to the piston. On one side, the piston (36) defines a pressure chamber (38) with a pressure outlet (48) provided for connection to a brake circuit. On the other side opposite the actuating member (30), said piston defines a caster chamber (40). The piston (36) has a larger hydraulically active surface than that of the actuating member (30). A device enabling selective fluid connection between the pressure chamber and the caster chamber (40) establishes said connection when the brake booster (12) fails to work or malfunctions.